How Feasible Is Large-Scale Urban Farming?

As city-dwellers around the world discover the importance of locally-grown food, visions of self-sustaining cities continue to grow. But how feasible is urban farming on a large scale? According to this video based on research from MVRDV, The Why Factory, and Stroom Den Haag, not very. In the end, the video concludes that "To strive for complete self-reliance with food in cities is currently not sensible", but still worth pursuing. Decide for yourself after watching the clip below.